The definitin of chronic cough is that people had cough more than 3 weeks without obvious evidence of pulmonary disease. Cough is often the symptom that patients seek for help.

Cough is one of the most common clinical symptoms in the respiratory system.  Variant asthma is marked by cough only. The possibility of the disease should be ruled out first for chronic or recurrent cough.

Common Causes

• Upper airway cough syndromes (post nasal drip syndrome).
• Asthma or eosinophilic bronchitis.
• Chronic bronchitis and bronchiectasis.
• Acid regurgitation.
• Drug induced.

Other Etiologies

• Lung cancer (only 2% of patients with chronic cough).
• Pulmonary tuberculosis, interstitial lung disease, lung abscess, pulmonary fibrosis, aspiration pneumonia (in elderly and esophageal disease patients).
• Otolaryngological diseases (nasal polyps, external auditory canal disorders).
• Esophageal diverticula.
• Functional (psychogenic) cough.
• Benign tracheal tumors.
• Chronic infections
• Left-sided heart failure
• Foreign bodies

Treatment of Chronic Cough

Nonspecific cough medications are commonly used, such as: 1) nonspecific cough medications for central or peripheral nerves, or 2) medications for respiratory muscle motor neurons, or 3) medications for improving the ability to expectorate sputum.

Treatment of Upper Airway Cough Syndrome (Post Nasal Drip Syndrome)

Drug therapy

• Antihistamine + drugs that alleviate nasal congestion.
• Early antihistamines have greater side effects on the central nervous system, but they are more effective in treating this type of chronic cough than the newer generation of antihistamines.
• Efficacy is usually assessed after a week of use.

Treatment of Chronic Cough due to Gastroesophageal Reflux

Gastric acid reflux to the esophagus or airway can cause heartburn sensation , acid vomiting, and hiccup. In some patients, cough may be the only symptom (43%).

General treatment

• Avoid foods that may cause reflux. (fatty foods, chocolate, alcohol)
• Smoking cessation
• Avoid eating snacks 3 hours before sleeping or lying down.
• Elevating head of bed

Drug therapy

• H2 blockers or a new generation of drugs that inhibit gastric acid secretion
• Drug that accelerates gastric emptying: Cisapride.
• The average duration of treatment for cough relief is 3 to 6 months.
• A small number of patients who have failed treatment may require surgery.

Treatment of Chronic Cough Caused by Chronic Bronchitis

Chronic cough may be improval in 90 % of patients with chronic bronchitis who quit smoking.

Pharmacotherapy: bronchodilators, combined therapy with steroids and bronchodilators, antitussive drugs such as Codeine and Medicon.

Chronic Cough due to Bronchiectasis

The bronchus widens and even becomes cystic formation. Symptoms include cough with/without sputum, hemoptysis, fever and dyspnea. The quantity of patient's sputum is large and  the appearance is thick. A physical examination does not necessarily find abnormalities. Chest X-ray may detect some non-specific changes;  HRCT (high-resolution computed tomography ) is the most sensitive methoid for diagnosis.

Therapy: expectorant and bronchodilators, chest physical therapy, postural drainage, antibiotics.

Cough due to Side Effects of Medications

Angiotensin-converting-enzyme inhibitor (ACEI) (medication for bloodpressure control), can cause chronic cough. For these patients, their symptoims will improve, when they switch medication to ARA.

Treatment of Unexplained Chronic Cough

If the cause cannot be identified, the following drugs may be helpful:

• Non-opioid cough suppressants (inhaled steroids).
• Codeine may be administered to relieve cough if treatment fails.